So the first pic shows the large part of the rock, but it extends above and below creating a large foundation for part of my reef. The rock is over 1 foot tall. The 2nd pic shows how the zoas encroach onto neighboring rocks. I've cleaned up around those areas with tweezers on multiple occassions just to make sure the zoas don't take over more rocks.. The 3rd pic shows how the zoas snuck behind the main rock, climbed up the coraline on the back glass of the tank and reappeared on one of my highest pieces of rock and have grown up under an orange monti. If left unattended they will continue to take over that rock, which is my prime lit space for SPS. If I sold the rock I would probably need at least $40 or $50 just because live rock sells for $3-5/lb. The reason I was thinking about remove the zoas was because that rock just fits perfectly where I need it, and I really don't feel like going through the hastle of buying replacement rock. I would have no problem keeping a colony of these zoas in my tank, if they didn't spread so quickly. Great beginner coral though, because they are unbelievably hardy, and the green eye glows in actinic and LED moonlight..